Best Match: Magic & Chemistry
by WhiteRose-Aki
Summary: Ginny travels to another world and helps Sento to regain his lost memory and find a way home. But when she is suddenly involved with a war, Ginny must get help from a escaped prisoner and a strange girl with unique powers. HP/Build xover
1. The One with the Best Match

Well, I have no idea what to say expect this ought to be fun. Welcome to my Harry Potter/Build crossover, this one was suggested by MaryamSahibzada, who suggested that I do a HP/Build story with Miss Ginevra Molly Weasley as the lead, where she meets Sento and well, here it is. I honestly had no idea how to do this but I am going to treat the two franchises that will be in this story as separate worlds, cause in my head, I see all my favorite franchises being in one world, unless stated otherwise. So yeah, HP and Build are their own worlds.

Summary: Ginny Weasley is sent to another world and becomes the aid to the amnesic Sento Kiryu to help him fight against the Smashes and regain his lost memories. As she tries to help him, Ginny finds herself involved with the war between the three nations of Japan and finding help from a convicted prisoner and a strange man with his strange daughter. Can she find her way back to her world? Or is she stuck in this strange world ?

Pairings: We'll see what happens

Disclaimer: I own none of this, Harry Potter belongs to J. K. Rowling and Bloomsbury Publishing, Kamen Rider Build is owned by Toei TV and Shotaro Ishinomori. If I had owned anything of this, I have no idea where I would change.

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Best Match: Magic and Chemistry

Chapter 1 - The One with the Best Match

The rain was pouring hard and aside from the pitter-patter of the rain on his umbrella and the various items around the alleyway, the alleyway was quiet. A barista, wearing a green hat which hid his black hair and round sunglasses on his nose to cover his brown eyes, looked around after he had taken in a young man with no memory of his past, he had explained to his daughter that he was taking a second look around the area in case he had forgotten something. He wondered if he would find anything or thought that there was anything left to find the alleyway.

Hearing a soft moan, the barista listened and walked around, looking for the source of the moan. He looked around, walking a few steps and looked, gasping as he saw the source of the moan and couldn't believe what he had seen.

Finding a clean blanket, he wrapped it around the person he had found and carried the unconscious person back to his coffee shop, nascita. Luckily, there were no customers so he didn't need to worry about concerned look as he carried the person into the shop and behind the counter, walking to a small fridge hidden in the back of the shop. He opened the door and knelt down, going down a spiral staircase and saw his daughter, who had black hair in a up do and brown eyes in a white dress, look up from watching the strange black haired young man on the bed.

"Who is that, dad?" She asked, looking at him. He smiled, "Another member of our ever growing family." He carefully laid the person on the bed next to the young man, and revealed it was a young woman with long flaming red hair, her face covered in a dusting of freckles, wearing a school uniform of some kind and was breathing soundly like the man. The older man covered his mouth and hid a smile, thinking about what to do with this girl.

-A Year Later-

Ever since that day, the two had stayed hidden in the basement of nascita, helping each other, the girl helping the boy regain his lost memories due to her having all her memories expect when she had arrived in the city whereas he did not. And they also became friends with the two residents of the coffee shop, the owner, Soichi Isurugi, and his daughter, Misora Isurugi as well becoming friends with each others.

Despite how long they had helped each other, the girl thought she had growing feelings for the boy she shared the basement with, but she doubted that he felt the same since he was busy with inventions and she thought that he reminded her of a annoying school bully from her old school. When it came to outfits to wear, the girl revealed that she could do magic and change her clothes into something more suitable though she was also a small wardrobe to wear though she kept the robe and necktie she wore as is.

Another unique thing about the girl was that she spoke, the three learned that she was British and could only speak English, thus began to teach her to speak Japanese. Within no time, she began to speak fluent Japanese and did her best to help her new friends and family. At some point, she bore witness to the boy getting a unique belt and a few small bottles, the boy being asked to use them for heroic purposes and that she support and help him in anyway.

As she learned to speak the language, there was another thing the girl learned about where she was. 10 years prior, there was a incident known as the Sky Wall Incident during which a wall appeared and separated Japan into three country, Hokuto, the northern country which dealt with social welfare, Seito, the southern western country that worked with economic recovery, and Touto, the eastern country which practiced traditional pacifism and was where the cafe was located.

As she finished putting her flaming red hair into a braid, the girl looked at her reflection, noting how much she had grown within the past year, her brown eyes looking at her reflection. Her face covered in a dusting of freckles, her long red hair braided back into a ponytail, she wore a gray short sleeved shirt that exposed her shoulders with the red and gold necktie wrapped around her right bicep while she wore around a white asymmetric skirt with tan leggings and brown slip-on trainers on her feet. She grabbed the robe which had been changed into a black overcoat, the house crest had become a patch on the sleeve.

Upon hearing a gasp, the girl left the curtain covered area of the lab that was labeled 'Changing Room' and headed to the part of the room which had two beds and a work area, seeing her companion sitting at the desk as the toaster popped up with his breakfast. She asked, "Sento, are you okay?"

Sento turned to look at her and she was speechless as his face was covered in marker doodles, he said, "Yeah, I'm fine, Gin-chan. Just a bad dream and a bad memory." "Uh, Sento, your face..." Ginny pointed to which he looked at a mirror and saw what had happened to his face. He groaned, "This sucks!" Ginny laughed and dampened a towel to clean his face as he ate a piece of toast and there was a ding as a microwave door opened with smoke coming out. Sento smiled and went over to check the results, grabbing a small white bottle with a black top and bottom.

Ginny sighed as he messed with his hair and said, "Awesome!" She didn't look as a tuft of his hair stood up and the door of the large machine next to it opened, revealing a tired looking Misora as she rubbed her gold bracelet. Sento attempted to give her a hi-five as he said, "Good job!" But she ignored it and walked past him, Ginny asked, "Is that from the monster that you fought last night?" "Yup." Sento said, smiling and showed her the bottle. Then he looked to Misora and asked, "What is this? A hedgehog?" "Don't know..." Misora said, tired and leaning against a pillar. "Don't care. Tired. Want my pay. Sleepy."

Smiling, Ginny finished dampening the towel and Sento said, excited, "What techniques will this have?!" "Sento, how bout we clean up your face first, okay?" Ginny said, walking to him and wiping his face of the marker doodles. Once she was done, Sento smiled and said, "Thanks, Gin-chan. I can't wait to try it!" Ginny shook her head, smiling as she cleaned the towel and hung it to dry.

"But you know, Gin-chan." Sento said, walking over to the machine. "My inventions really are the greatest." "I know, I know." Ginny said, smiling. Sento continued, "With just a few components from the monster, I can create power-up items for Build to use! Of course it's thanks to the strange power that Misora has. But it's all due to my abilities that I can take it to max-" But they saw that Misora had fallen asleep on his bed and Ginny sweatdropped as he got a smile, "Now then."

After a few minutes, the two put on their overcoats and headed up the stairs, Sento having a small smile on his face as he ate the other piece of toast. Soichi came in from sweeping the front of the cafe and looked as Ginny and Sento came out of the secret fridge in the back. As they walked, they jumped and held each other in shock as Soichi appeared, jumping from the other side of the counter. "Buongiorno, Sento-kun! Ginny-chan!" "Soichi-san..." Ginny said, catching her breath as she and Sento let go of each other, Sento said, "You surprised us!" He looked and showed him the bottle, "Here! Results from yesterday."

Taking the bottle and examining it, he smiled and said, looking down at the secret fridge, "Bravo! My dear child! Thank you!" As they sat at the counter, Soichi looked at Sento and asked, "So? Did you remember anything?" "What?" Sento asked, Soichi sighed and said, "Your memory! The twenty-odd years of me-mo-ry you're missing." Ginny laughed and looked at him, Sento thought and said, "A scientist with a gas mask, human testing, and a bat man." But then he sighed, having nothing else to say, Soichi said, "No progress then?"

Ginny touched Sento's shoulder to calm him and he touched her hand, Soichi said, "You created Build to search for that bat man!" Sento sighed and said, "Even when I change the people turned into Smash back to normal, I don't remember anything." Ginny looked down with him as they kept quiet, Soichi interrupted their moment as he said, "And by the way, you've racked up a year's worth of rent." "Wait, when you were renting the basement to us?!" Ginny asked as Sento looked over the checks and said, "What rent?! You were charging us?!" "Of course it does!" Soichi said, smiling at them. "I'm not softhearted enough to let a amnesiac and homeless girl stay free of charge."

"Is that why you made me get a job at the Institute?" Sento said, looking shocked. Soichi said, "It's your first day, isn't it? Should you be lazing about?" Sento looked at his watch and gasped, "Oh crap!" He got off his chair and went to the door but turned around and said, "So when you're in a hurry, you should use..." He revealed his new inventions, "This!" He revealed a cellphone and a yellow bottle, Soichi asked, "What is that? You gonna call in sick?"

"Yeah!" Sento said, putting the phone to his ear but stopped. "Of course not! It's my invention!" "What does it do?" Ginny asked, looking curious. Sento put the bottle into a indent on the side and tossed the phone in the air, hearing something, 'Build Change!' and a motorcycle appeared, Ginny and Soichi were impressed and awed, Sento smiled, "Right?! It's amazing!" "It's fantastic!" Soichi said, Ginny nodded, "It's wonderful." "Indeed, it's genius!" Soichi said as Sento pressed on a touch screen and a helmet appeared, then he mounted the motorcycle, ready to go til the three of them realized something.

"Sento, you idiot!" Ginny said, hitting him with her fist. "You demonstrated inside the cafe!" Soichi laughed and the motorcycle was moved outside, Ginny gave him a tight hug before he left and she waved at him. She hesitantly lowered her hand and breathed, heading back into the cafe and went into the basement lab. She sat at the computer in the lab and watched the news report of the jailbreak of Ryuuga Banjo who had been sentenced to ten years of jail for a crime that he had committed.

She looked at the footage of Ryuga supposedly defeating the guards that were after him, she thought, 'Could he really do that? Sento, be careful...' Soichi and Misora joined her at the computer and looked at the footage, contacting Sento, Soichi said, "Ryuga Banjo. A former martial artist. He was given a perma-ban for fixing games and sentenced to ten years of hard labor for killing a scientist a year ago. The sensor is responding, but there aren't any eyewitness reports of a monster. He might not have become a Smash yet. I hacked into the GPS of the motorcycle Banjo stole, so I'll send you the data."

Ginny got up and ran upstairs to a quad bike she had gotten from Soichi, putting her helmet and going after Sento. Following the direction that Soichi gave her, Ginny arrived where Sento was and saw him shake a blue and red bottle, a unique looking belt around his belt, then turned the taps before inserting them into the belt, with the announcement, "Rabbit! Tank! Best Match!" He suddenly grabbed the level and spun it, starting it slow then went faster.

As a building kit appeared around him, the half in front of him being red and the half behind being blue, it asked, "Are you ready?!" "Transform!" Sento shouted, then the two halves came together on him, giving him the blue and red armor, announcing, "Steel Moonsault. Rabbit Tank! Yeah!" "Go... Sento..." She said, softly, watching him face against the Smash that was in front of him and saw Ryuuga in dirty white clothes, bewildered.

She watched as a drill-shaped sword appeared from his belt and slashed at the Smash. Ginny noted that he removed the Rabbit bottle and brought the Hedgehog bottle, inserting it and spun the lever. "Build up!" He said, as the red become white with spikes. Ginny looked surprised and thought, 'So, there can be more than one Best Match with certain FullBottles.' She looked, watching the fight as he used the new bottle to fight.

Using the abilities of the new bottle, like the fist it gave with the spikes, Sento sent it back and shook a red bottle, saying, "I'll finish you with this." He went back to Rabbit Tank and spun the lever of the belt, before going, "Wait a sec." He ran a distance from the Smash then jumped into the ground as a white chart appeared with the dotted line trapping the Smash. Then Sento jumped and slid along the dotted line, destroying the Smash.

Ginny watched him take a empty bottle and used it to gather the essence of the Smash to reveal the unconscious human who was on the ground. He seemed to notice her and looked at her, realizing that she had been noticed, Ginny ran to Sento and looked at the young man who was once the Smash and he had no idea where he was, Ryuga looked at Sento and said, "It's true! They did something to both of us!" Ginny and Sento kept quiet, since they weren't sure what to say. Ginny looked at Sento as Ryuga grabbed his shoulders, "Believe me!"

"If what you say is true," Sento said. "Then that was the Smash's human experimentation..." Ginny gasped, looking at him. Suddenly the guards appeared and Ginny hid behind him as one of the windows of the car rolled and a voice asked, "So you're the Kamen Rider?" Appearing was a bearded man in a gray uniform, "I heard about you. We'd appreciate it if you'd hand over the murderer Ryuga Banjo." "I didn't kill anyone!" Ryuga shouted.

The man clapped his hands and all the guns were pointed at Ryuga, he sobbed, "I am a worthless piece of idiot garage... but I would never kill anyone. Why... why won't anyone believe me?!" Seeing how quiet he was, Ginny asked, "Sento?" He sighed and knelt down, "This sucks!" Giny and Ryuga looked at him as he said, "I'm totally gonna regret this later." He summoned his motorcycle and told Ryuga, "Get on!" He nodded at Ginny and she went to her quad bike, getting on it then followed after Sento.

Quickly they were followed and Ginny gasped, trying to drive straight as they were shot at and had rockets shot at them, she shouted, "They're crazy!" As they rode up a ramp on the Sky Wall, then rode down on the side, Ginny thought, 'Strike that, Sento's crazy!' Luckily Sento caught her and Ryuga as he used his sword as a brake, his motorcycle stopping her quad bike to land before becoming a phone and landing perfectly while the last pursuer fell to the ground. Once the three were on the ground, they rode off to the nascita.

"Damn, now I'm a fugitive, too." Sento grumbled, Ryuga asked him, "Why did you save me?" "I believe you." Sento said, as Ginny looked at him. "That's all." Then he added, "A real idiot doesn't call himself an idiot. You're not a liar." He gave a chuckle, "Although your fly is open." Ginny looked away, as Ryuga noticed and said, "Since when?!" "Since the beginning." Sento said, Ryuga whined, "Why didn't you tell me?!" "The timing wasn't right." Sento told him. "Figure it out for yourself, idiot."

Ginny just smiled, riding along side him as Ryuga shook him, trying to tell him that he wasn't a idiot. None of them knew of the black bat figured that watched them before disappearing.

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And so the story begins, oh I can't wait til Ginny gets the funnier part of the story with Gentoku being a weird silent man and witnessing Kazumi being a otaku fanboy over Misora's Mii-tan idol persona. Well, gonna have to wait and see.

Next chapter, Sento's role as Kamen Rider is now considered a wanted criminal, Ryuga tries to retrace his step about his arrest, Ginny worries about Sento getting caught, the group thinks Ryuga has been framed. This has been WhiteRose-Aki, see you in the next chapter. Please R&R if you enjoyed.


	2. Innocent Runaway

Welcome to chapter 2 of the story. When I first saw this episode, I couldn't believe how dumb Ryuga was by thinking he had to explain everything from the start of his life. I was like, 'Dude, Sento obviously meant tell everything from the moment you got arrested.' But he does have his moments of being smart especially with how he tricked Misora so he could take her phone to get away. There was a lot of laughs at the start of Build, and it's gonna be fun when we get to the later part of the story. -nervously laughs-

Anyway, big thank you for the people who Favorited and followed the story and a big thank you with a hug to MaryamSahibzada for the review for me to write this chapter. I really hope we can enjoy how this adventure will turn out with Ginny helping Sento and the Build cast.

Disclaimer, I do not own any of this. Harry Potter belongs to J. K. Rowling and Bloomsbury Publishing, Kamen Rider Build belongs to Toei and Shotaro Ishinomori. All I own is the love of the two series, idea of mixing them together, and nothing much else.

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Chapter 2 - Innocent Runaway

As soon as Ginny, Sento, and Ryuga got to nascita and headed into the underground lab, Ryuga washed himself up and got dressed in fresh clothes, then wandered around the lab. While he looked around, Soichi whispered to Ginny and Sento, "Hey, hey, hey, hey! Do you realize what a mess you've made?!" "I didn't have a choice!" Sento protested. "If I had just handed him over, he would've gone straight back to prison! He'd just get used as their guinea pig again." "In all fairness, Soichi-san, us bringing him here is much better than that." Ginny reasoned, looking at him.

"What do you mean, guinea pig?" Soichi asked, looking at them. Sento said, "What he went through was the best match for my memory. I think I was a test subject too." "But if they had done anything to you, both of you would've become monsters!" Soichi told them, looking worried. "Plus he hasn't lost his memory. If he has his memory, then he must know where their base is!" "Though it seems from what he told Sento, he was knocked out before getting tested on." Ginny told him. Sento agreed, "He doesn't remember the place. But if we try to unravel the murder Banjo was caught in, it might lead us to the bat man's organization."

Ginny looked at him and wasn't sure if it was a good idea, but didn't say anything. They went to Ryuga, Sento saying, "Hey!" He turned Ryuga around to see him messing with some of the stuff in the lab, Ginny sighed, even Sento sighed and said, "For now, tell us your story." "Tell you what exactly?" Ryuga asked, confused "Everything." Sento said, simply. Ginny tugged at his sleeve and whispered, "I think you should have worded that better." Sento looked at her confused.

"Fine," Ryuga said, finding a chair to sit in. Then he began to explain, "I was born in a maternity hospital in Yokohama. I was healthy 3203 gram baby-" "No one asked for your whole life!" Sento shouted, stopping him from recounting every moment from his childhood. Ginny smiled, and laughed, amazed that he could recall such details from his birth since she could barely her first steps as a baby.

"But you told me to tell you everything!" Ryuga argued, Sento said, sighing, "Figure it out from context, idiot!" "You seem to have taken it a bit too literally." Ginny told him, watching Ryuga shake Sento, saying, "Idiot?! Who's an idiot?!" Ginny sighed, shaking her head, not wanting to say that it was Ryuga's own fault and took it too literally by thinking he had to talk about his life from the day he was born up til recently. Soichi looked at her and shook his head, taking her to sit down in a pair of chairs.

"Don't focus on very little detail." Sento said. "Tell us how you were arrested." "Oh." Ryuga said, now realizing what he meant and said, "I was introduced to the scientist for a job. When I went to his place, he was already dead. Then the cops showed up-" "Objection!" Soichi said, showing himself from the bedroom and Ginny looked at him, asking him, "What's wrong?", being confused and curious at what he was getting at.

"Yes, master?!" Sento said, pointing at him. Soichi inputted his thought about Ryuga's situation, "That's a bit too convenient, the cops showing up to the scene just as you get there." "That's really when they came!" Ryuga shouted, Ginny groaned, he said, "Do I sound like I'm ly-" But at that moment, the microwave sounded and a FullBottle was ready, so Sento pushed Ryuga aside to get and examine the new FullBottle.

"That Smash became Gorilla!" He said, smiling as he held the red bottle in his hand. He smiled and petted his invention, saying, "Well done!" But the door opened and Misora stepped out, slapping his hand which Ginny gave a chuckle at. She looked at him and said, "You know that's all thanks to me! Move it." She stepped down from the machine, however, due to not seeing her, Ryuga shouted and pointed at her.

"Who are you?!" He shouted, shocked. Misora looked at him and held up her fists, shocking him, she said calmly, "That's my line." Sento and Ginny looked at each other as they recalled their reactions when they first met each other and Sento spoke, "Anyway, if both the murder and his jailbreak were set up, then there must be some commonality." "Like what?" Ginny asked, Sento said, "Not sure. We'll need to investigate that. Now where to start?"

The room was quiet for a moment when a new voice spoke, "Then let me help you out." "Who are you?!" Sento shouted, as a young woman with short brown hair and brown eyes appeared, she smiled and waved. Soichi and Sento looked at each other, trying to figure out how she got in. Ginny looked at Sento, narrowing her eyes. Misora hit her father, saying, "Why'd you leave the door open?!"

"I locked it!" Soichi said, proclaiming his innocence as Ginny, Sento, and Misora looked at him. "Sento and Ginny-chan brought this guy in, 'Hey, don't just bring someone into the base!', and then I ran after you two, opened the door and..." It took him a few moments to realize his mistake, "I didn't close it!" "Come on!" Sento said, hitting his chest. Soichi leaned in with his hands together, "Sorry!" Ginny sighed and looked at the woman as she stepped into the lab and smiled, looking around the area.

"So this is the Kamen Rider's base?" She said, looking and smiling. Ginny looked at her and asked, "How did you know that?" The woman looked at Sento, and said, "Did you forget about last night at the har-bor~?" With the way she said it, Sento stiffened as he felt daggers getting tossed at him from behind and cleared his throat, saying, "Oh! How you'd find this place?" The woman smiled and showed a small match box with the name of the cafe on it, saying, "You dropped this."

"Come on!" Soichi said, looking at him after he had the nerve to accuse him. Sento copied what he did earlier and said, "Sorry!", while trying to ingore the especially sharp stab to the chest he guessed from the red haired girl behind him. The woman said, "Don't worry! I just came here to say thank you! Alright... I'd be thrilled if you let me cover the Kamen Rider for an article..."

Sento turned and said, "Nope." "Please!" The woman said, pleading with him. "I'm at a critical point in my freelance career! I need something special!" But Sento just rolled his eyes and walked from her, the woman breathed and said, "If you don't give me exclusive coverage, I'll reveal your secret." "Damn, it seems like she has us there." Ginny groaned, and sighed since she was using that as her trump card against them. Misora looked at the woman and said, "How refreshingly shameless."

"Okay, fine." Soichi said, sighing. Misora looked at her father and said, "It is totally not fine." "Misora, we have no choice, we'll need to accept to keep this secret." Ginny said, looking at her. Soichi nodded, saying, "Can't be helped! But only as long as you don't reveal our identities." "So, it's win-win for both of us!" The woman said, smiling and making two V signs with her fingers. She looked at Sento and said, "Right?" "This sucks." Sento said, pouting.

So after that and making a bed for Ryuga to use, Sento was about to go to bed and saw that Ginny wasn't facing as she laid on her bed. He sighed and guessed he deserved it since usually, they would sleep facing each other and hold each other's hand to reassure each other everything would be alright, they had done it every night since they had met. During the year, he thought there was some kind of connection between them but he didn't feel it since he was busy with his duties as Kamen Rider and working on his inventions, so he thought maybe Ginny didn't feel anything for him. Sento laid on his bed and held out his hand just in case she still wanted to hold his hand during the night. So during the night, Sento dreamed that someone did held his hand, unaware that Ginny rolled over and held his hand.

The next day, Sento headed out early and went to the location the woman told him about, but was confused. "Hey, no one's there!" Sento called the base, Soichi and Ginny were at the computer and Ginny was confused, she said, "That can't be right. There was a eyewitness report of a Smash there." When he was suddenly cut off, Ginny sighed and leaned back in her seat, covering her face while Soichi left the base for something, she tried to ignore Ryuga struggle as he was chained up by one of the pillar.

"What's with the chains?!" He shouted. "Take them off!"

"Can't." Misora said, simply as she looked at her phone. "Still don't trust you. Don't wanna get attacked." Ginny smiled and looked at her, still amazed at how simple she was. Ryuga shouted, "Who'd attack you?! Anyway, who are you guys?" "Heroes of justice who protect Touto." Misorsa said, looking at her phone. Ginny said, "Something like that." "What bout you?" Ryuga said, looking at her. Ginny sighed. "Sento and I were found on the same day and we have been helping each other since the day. I've been helping him trying to regain his lost memories while he has been trying to help me find a way back home. I don't understand everything that we're doing, but I try to help as best as I can."

"Read this for details." Misora said, showing him a board. Ryuga grabbed it with his feet since it was swinging around while Misora held it, he began to read, "'To return Smash to human form, defeat them and take out that element. Purify the bottled element in the conversion device and it can be used by the Kamen Rider.'" "That's the gist of why Sento fights the Smashs." Ginny said, and Misora nodded, "And I am the only one who can purify it. I have the power to do so."

"We don't understand why it is." Ginny said, putting a finger to her chin. "But Misora is awesome for that." Seeing as Ginny wasn't looking at them and Misora was looking at her bracelet with her phone on the floor, Ryuga smiled and said, "Oh, really?" "What?" Misora said, looking at him. Ginny looked and sighed, Ryuga said, "There's no way a kid like you can do that! Prove it and make one now! Or is it all a lie?" "Are you being serious right now?" Ginny asked, looking at him.

"It's no lie!" Misora said, looking at him. "I'll do it. Once it's finished, you'd better pay my hourly wage." "I won't do it, Misora." Ginny said, but it fell on deaf ears as Misora put a bottle in the conversion device and stepped in on the other side. As Ginny hid her face, sighing in defeat and going to stand in front of the device, Ryuga used Misora's phone to call someone. Getting upset by something from what the other person on the other line said, Ryuga struggled and broke his chains, escaping and took Misora's phone.

When she stepped out, the two girls found out that he had escaped and Ginny groaned, "I knew it." She revealed her own smartphone, which had a phone case being light brown with the strange crest that she wore on her robe and called Sento's phone, Misora looked at her and wondered when did she get her own smartphone, Ginny whispered, "Sento gave it to me a few weeks ago." Hearing Sento pick up, Ginny explained, "Sento, Banjou ran away! He took Misora's phone, so use its GPS to track him down. I'll be heading out soon to follow." She grabbed her helmet and went upstairs, smiling to see that he hadn't taken her quad bike.

Sento quickly met with her and they soon found where Ryuga was, heading into a abandoned building and Sento was quick to fight back, switching the blade of his sword to the other end and using it as a gun. Ginny joined it by bringing out a stick and murmuring something, sending powerful spells. "Banjou, what the bloody hell?!" She shouted, Sento said, "Why'd you run away?!" "I had to!" Ryuga said, as the three of them were fighting off the guards. "I got a girl waiting for me!" "A girl?!" Sento asked, surprised as he took out another guard.

The three of them ran out and saw a new patch of guards marching, Ginny groaned, "You've got to be kidding." She groaned more as they tore off their uniforms and formed together to make a mech, seeing how big their new formed opponent was, Sento said, "This sucks." When it began to fire on them, Sento grabbed Ginny's hand and they ran from the area with Ryuga. Rolling into a empty building, Sento let go of Ginny's hand and brought out two bottles, saying, "So, shall we begin the experiment?"

Ryuga and Ginny made it to their bikes, looking at Sento change into a brown and crystal blue form, Ginny thought about what she heard of the change, 'Gorilla and Diamond, huh? Interesting match.' They followed him outside, where he had formulated the plan to defeat it, Ryuga looked at him and said, "Get on!" "Sorry, but go back!" Sento said, punching his bike to go on. Ginny looked at him, "Sento?" "Gin-chan, go on back ahead of me." Sento said. "I'll be fine. Also, I didn't mean for that reporter to find the base. I'm sorry." "I forgive you..." Ginny looked at him and smiled. They nodded at each other and she went after Ryuga, the large mech shooting at them as they rode through the building.

After safely getting out of the building and seeing Sento beat the mech, Ginny and Ryuga met him in a empty alley. She looked at him as he came up and Ryuga sighed, Sento said, looking at Ryuga, "So... Who's this girl you were talking about?" "Kasumi Ogura." Ryuga said, thinking about her. "The one who introduced me to that scientist and the one who sent me to the place he was killed was Kasumi." "Not to be mean, but is it, well, you know?" Ginny said, looking at him from her quad bike. Sento said, "Why didn't you say any-" But Ryuga stopped him, punching him and holding him in a headlock til he passed out.

Ginny gasped and ran to him, holding him in her arms, Ryuga looked at them and said, "Sorry. This is my problem." Ginny watched him get on his bike and rode off, she kept quiet and waited til Sento groaned and woke up in her arms. She simply said, "He went to meet her but I have a bad feeling about it." "Then lets go and stop him together." Sento said, smiling as he summoned his bike and she got on her quad bike.

The two of them drove out to the location and knocked a new Smash to the ground, they looked at the surprised Ryuga on the ground, Sento said, "Dammit, stop running away! You wanna die that badly?!" They drove off to distract the Smash and Sento went back, hitting it with his front wheel. Ginny looked as he changed into his form as Kamen Rider, Ryuga shouted, "Stop! That's Kasumi!" "What?!" Ginny shouted, looking at the Smash. Then a mist appeared, forming a being in black armor with a yellow bat-shaped visor, the smoke seemed to come from the pipes on his forehead and shoulders.

"Bat man..." Sento said, Ginny gasped, the being introduced itself, "I am Night Rouge." "Don't care!" Sento shouted, changing into a form with Hedgehog and Tank. He began to fight with Night Rouge and Night Rouge proved to be stronger then what Sento seemed to expect, he said, "What did you do to my body?! You used me in your experiments, didn't you?!" "I can't remember every single guinea pig." Night Rouge said, Sento shouted, "Don't mess with me!" Ginny watched, looking at him, worried.

"Don't think you can win against me with a random chosen bottle." Night Rouge said, using the smoke to summon a sword. Ginny gasped, watching him swing his sword and attack Sento, sending him rolling. She shouted, "Sento!" He saw and looked at Ryuga, getting him out of the way from the Smash's attack. Sento was going to attack, but Ryuga shouted, "Stop it! That's Kasumi!" "Banjou, he has to!" Ginny shouted. "It's the only way to bring her back!" "Yes, if I remove the Smash element, she'll return to normal!" Sento said, looking at him.

But Night Rouge fired at him, saying, "If you do that, the woman will disappear." "What?" Ginny and Sento said at the same time, Night Rouge said, "Hazard Level 1. The gas is fatal when injected into weak humans. If you remove the Smash element, her soul will disappear along with her body. There is no way to save her." Ginny was shocked, covering her mouth. Ryuga said, shocked, "No..."

Sento was going to attack, but Ryuga went in front of the Smash, shouting, "Stop it!" "Banjou..." Ginny said, looking at him and saw that the Smash was struggling with its power. Ginny covered her mouth as Ryuga wondered, "What's going on?" "Once someone turns into a Smash, their personality disappears." Sento explained. "But it hurt itself instead of hurting you." "Why?" Ryuga said, the area was quiet as they saw the Smash struggling with itself. Ryuga said, "Hey... Can she really not be saved?" Ginny and Sento were quiet for a moment.

"If not," Ryuga said, trying not to choke in his sadness as he turned to Sento. "At least return her to normal!" "Banjou..." Ginny said, looking at him. He bowed, "Please!" Ryuga and Ginny watched as Sento changed his form to Rabbit and a vacuum cleaner, the vacuum getting the fire balls that appeared. Upon getting all the fire, Sento changed back into Gorilla Diamond, which changed the fire into diamonds then activated his finishing move. He punched the diamonds to the Smash and the Smash was removed, revealing the young woman who had changed into that form.

Ginny slowly stepped forward as Ryuga talked with Kasumi, she was glowing and slowly fading as Sento kept the Smash reentering her body. Before Sento fell to his knees, Kasumi disappeared, Sento sent the Smash flying and Ginny walked to them as Ryuga cried, "Why...? We were going to see the cherry blossoms again..." Ginny and Sento kept quiet as Sento collected the Smash essence, he sighed and said, "Let's go." He looked at Ginny and she looked down, Ryuga said, "It's fine..."

Ginny and Sento looked at him, Ryuga said, crying, "It's fine..." "What?" Sento said, walking to him. Ginny touched his shoulder, but Sento grabbed his shirt, "What's fine?! It's not fine! If they catch you now, you'll still be a murderer! You fine with that?" Ginny looked down and kept quiet, holding her arm. Sento shouted, "You think she'll be happy about that?!" He tossed him and took Ginny's hand, leading her to their bikes. As they got ready to head back, Ginny looked with Sento as Ryuga appeared and got on his bike.

The three of them kept quiet and rode off, driving back to the cafe. When they got back to the base, Ginny and Sento were quiet, not saying anything to each other as Ginny wasn't sure what to say to Sento and sat at the computer, thinking about her family. Ryuga walked up to them, he said, "Thanks to you, I was able to talk with Kasumi one last time. Thank you." But noticing Sento not saying anything, he walked to him and said, "Are you sleeping?!" Ginny laughed.

The conversion device sounded, and Ryuga jumped, holding Sento in surprise as he opened his eyes. They stood up together and Sento said, "The bottle!" Getting Ryuga off him, Sento went and got the bottle, examining it. Ginny said, "What is it?" "Dragon?" Sento wondered, Misora stepped out and she didn't say, stepping down. Sento pondered, "Ryuga's ryuu, huh?" He tossed it to Ryuga and said, "That's the element I removed from her. You hold onto it. Thank me after your charges are dropped."

Everyone in the room smiled and looked as the woman came in, "Hey. I found the guard who drugged Banjou. His name is Nabeshima Masahiro." She showed a pair of photos, Sento and Ryuga took the photos and looked at them, Sento said, "We've discovered the connection your jailbreak and the murder." Ginny looked at him, worried.

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If I'm gonna be honest, I was speechless when Ryuga asked that his girlfriend be turned back to normal so they could say goodbye. Then I smiled cause Sento gave him the Dragon FullBottle as a reminder of her. Sento is so kind. I hope Ginny is able to handle the twists and surprises when I manage to get that far.

Next chapter, the investigation starts for the man who possibly framed Ryuga, a connection between the murder and the experiment appears, a unexpected person reveals information needed. This has been WhiteRose-Aki, see you all in the next chapter. Please R&R if you enjoyed it


	3. Borderline of Justice

Finally, we have a new chapter here! My excuse for why this is late is because I am now volunteering at a elementary school for experience and also, I have archery and bowling, so my life has gotten a bit busier. Also, I have been spending too much time listening to the songs of the Greatest Showman and imagining the cast of Build singing them. As well as starting to watch Zi-O. But I am trying to write this and make sure it gets done.

Anyway, thanks to everyone who has followed and Favorited this story, and as for the reviews:

TheOkWriter - I know the phrase is Henshin, I was going off of the subs of the episode I was using at the time which had Transform rather than Henshin.

MaryamSahibzada - Yeah, I honestly have no clue on what to say about Zi-O cause I have barely watched it and well, it's a unique idea to me. I'll probably find a time to catch up on it.

meredinoemiliano - Thanks for your kind words. I hope you will enjoy this story.

Disclaimer is I own nothing of this, Harry Potter is owned by J. K. Rowling and Bloomsbury Publishing, Kamen Rider is owned by Shotaro Ishinomori and Toei TV, all I own is the idea, the crossover, and nothing much else.

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Chapter 3 - Borderline of Justice

"Okay? Listen carefully." Sento said to Ryuga as Ginny stepped out of the changing room, Misora was in one of the chair and the woman reporter, Takiwaga Sawa, was applying a ointment on her foot. Ryuga diligently sat on the floor and nodded, "Okay." Behind Sento was a clear board that had cartoony drawings, charts and arrows about everything that they knew of his forced imprisonment and how he got into prison. Sento pointed to the board with a marker, hoping to get Ryuga to understand his situation.

"The one who used your girlfriend to make you go to the scene of the scientist Takumi Katsuragi's murder was Nabeshima." He explained, Ryuga nodded. Sento continued, "And the one who knocked out at the penitentiary so he could bring you to the Smash laboratory was also Nabeshima! There's no doubt he holds the key to this mystery!" "I get it!" Ryuga said, standing up and smiling. Ginny looked at the brunette male and asked, "Do you really?" Sento sighed and shook his head.

"Nabeshima's resume was all lies," Misora reminded them, Sawa was surprised, "No way!" "I checked the adresss and phone number. They were both different people." "Well, that's no good." Ginny said, sighing. Sawa pouted and fell to the ground, crying, "But I went through so much trouble to get this..." Sento knelt down to her and patted her shoulder. Looking tired as usual, Misora said, "If you pay my hourly wage, I can gather information for you." 'Dang, Misora is cold.' Ginny thought, looking at her.

Laughing, Ryuga asked, "What can a shut-in kid like you do?" "Objection!" Isurugi shouted, jumping into sight. Everyone jumped at his sudden appearance. Sento said, "Yes, Master?" "Don't you look down on Misora-chan's power." Isurugi said, walking into the room. Ginny closed her eyes and Sawa covered Ryuga's eyes as Misora changed clothes and Isurugi suddenly began to record her, she smiled and said, "Hey~! It's everyone's idol, Miitan!"

"Misora-chan is a very popular net idol!" Isurugi said to Ryuga, Ryuga looked shocked, "Net idol?!" He nearly walked into the broadcast, but Ginny and Sento grabbed him and pulled him back. Sawa smiled to see who the idol was, taking photos, "The request idol that never meets anyone, Miitan!" "Hundreds of thousands of fans across the country gather information for Misora-chan." Isuguri whispered to Ryuga, Ginny looked as Misora asked her many fans for information on Nabeshima. And almost in a instant, there were a flood of messages and Misora gasped, "A Smash appeared in Area C9! Thanks for the information, 'Love Miitan'-san!"

"Alright, it's time for Build." Sento said, stepping forward. Ginny grabbed his arm and looked at him, worried. Sento smiled and held her hand, Ryuga shouted, "Hey! Wait! Weren't we gonna search for Nabeshima? Don't you want to know why you lost your memories?" "That's a different matter." Sento said, starting to climb the stairs. Ryuga shouted, "The rescuer Build or your past, which is more important?!" "Build, of course." Sento said, chuckling. Ginny looked away and sighed, sitting on one of the chairs.

'Maybe it is wrong for me to think there could be anything more between us.' She thought to herself. 'All that matters to Sento is being Build and stopping Smashs.' Ginny leaned back in the chair and waited for Sento to return, thinking back to her family and friend, wondering if they were looking for her and if they were worried about her having suddenly disappeared. Closing her eyes, Ginny began to sleep, napping til Sento returned to the basement.

Waking up to him working on something and Misora was converting a FullBottle in the device, Ginny heard Ryuga said, "Hey! We're fugitives, you know. Why did you need to save people?! We finally got a lead on Nabeshima-" He jumped when the device dinged, he groaned, "Seriously?! Why do you keeping that?!" Ginny hid a laugh, as Sento smiled at his new power-up, "Spoils of war, get!" "What's the new element this time?" Ginny asked, Sento looked at it. "It's a hawk this time?" She sweatdropped at him hugging his device, "You're the best~" The door opened and Misora stepped out, "Tired. Sleepy." She stepped on Ryuga, saying, "Going to bed."

She sat on Ginny's bed and put a sleep mask, saying, "Wake me... and I cut you." "I wish I could show Miitan's fans this." Sento said, going to put the FullBottles in a panel on the wall. Ginny sighed and shook her head. "Sento, don't." Ginny said, looking at him. "She deserves her privcy." "Hey." Ryuga asked, looking at them and standing up. "I've been wondering, just what is that?" "That's..." Isurugi said, suddenly appearing, "a Best Match. I'll say it again. A Best Match."

Ryuga said with a smile, "Still don't understand no matter how many times you repeat it." Ginny sighed, Isurugi said, "Bottles have their own affinity. For example, Rabbit and Tank. When we insert the two of them, it lights up like this if they have high affinity." He demonstrated by putting in the two bottles. Isuguri said, "If we get a best match with each pair, something amazing will happen. But they don't pair up that easily." "That's why we need this." Sento added, showing the Build Driver.

Ginny listened and nodded, Sento explained, "This was originally an analyzer I used for finding best matches, before I added the Build transformation function to it." Ginny watched as he inserted the Rabbit and Tank bottles, Sento stepped to Ryuga and asked, "What do you think of my invention?" "Well, I bet I can get it in one." Ryuga said, sounding dumbfounded. Sento laughed, "You've said it now, musclehead." Ryuga looked at him confused, but ignoring that, Sento said, "Then find one." 'This ought to be fun.' Ginny thought.

Sento showed a new weapon and explained, "I developed this to use Gatling Bottle, the ultimate weapon...!" After a moment of silence, Sento said, "Something Gatlinger... But I haven't found a best match for it." By some odd coincidence, when Ryuga put in Hawk and Gatling, it turned out to be a Best Match and Ginny covered her mouth in shock. Sento gasped, "No way!" "Bravo!" Isurugi said, silently clapping. Ryuga smiled smugly, "What do you think of my sixth sense?" "More like dumb luck." Ginny said quietly, Sento ignored that and said, "Taka Gatlinger? Hawk Gatlinger? Hawk Gatlinger sounds good. Let's go with that."

Before he could hit Sento, Isurugi stopped Ryuga and asked, "How did you know it was a best match?" Ginny looked at them and Ryuga said, "Well, if you must know... It's a living thing and a machine." 'Surprised he recalled that of a best match.' Ginny thought, looking a little surprised. Sento wasn't so amused, and said, "You can't possibly find a best match with such a childish way of thinking! To elucidate a best match, I need to use quantum mechanic paradoxes-" Suddenly there was a knife tossed into the wall and a grumpy tired Misora was standing in the room.

Ginny looked away and sighed, after the three were given their proper punishment, Sento went off to work and Ryuga was once again tied in chains. Ginny sighed, laying her head on the desk.

"Why are you doing this?!" Ryuga shouted, upset. Not hearing him, Misora smiled and said, "Nabeshima information kita!" Ginny looked at her and she explained, "Nabeshima worked for Naniwa Heavy Industries until one year ago. Oh, there's even a cellphone number." "Your fans are awesome!" Ryuga said in hopes of getting free. Misora stretched and said, "Time to sleep." Ginny laughed and Ryuga said, "Hey... Hey! A normal person would call Nabeshima!" "No use." Misora said simply. "Don't want to. No reason to help you further." So she went and laid on the bed. Ginny sighed and shook her head, 'Misora, a girl of few words.'

But Ryuga managed to break the chains, and walked to her, "Then I'll do it!" 'Whoa!' Ginny thought, standing up and watching him, getting ready to stop him. He took her phone and called the number, demanding that Nabeshima prove his innocence. Ginny groaned, 'He's worst than Ron when he's jealous of Harry.' However, they did learn that the name of the group who did experiments on him was called Faust, Ginny thought, 'That's the name of some old scientist or something. Hermione would know.'

"What are you going to do?" Misora asked, Ryuga grabbed the chains and walked to Misora, Ginny pulled out her wand and ran to him but he knocked her out. After a while, Ginny woke up to find Sento cradling her in his arms and Misora chained to one of the pillars. They learned about Ryuga was going to find Nabeshima's family. Ginny thought, 'Damn, he's persistent.' So Sento took Ginny with him to the harbor and he tried out the Hawk Gatlinger. Ryuga looked at him surprised, "Why're you here?!" "Get down." Sento said, as knelt down, Ginny pulled out her version of the gun and fired at the henchmem with Sento. Ginny breathed as Sento looked at Ryuga and asked, "What do you think of my invention?"

The three of them hid with Sawa as more of the henchmen appeared, Sento asked, "Those people who perform human experiments. They're called Faust?" "I heard from Misora." Ryuga said, Ginny asked, "Are you really going west?" "It's no use trying to stop me." Ryuga said, "I'm going to save Nabeshima's family from Faust." "Then let me tell you one thing." Sento said. "Ear to ear." "What?" Ryuga asked. Sento said, "When I help someone out, I become so happy that I grin from ear to ear. You just can't see it under the mask." After a moment, Sento said, "If you're expecting a reward, then it isn't justice."

However, a henchman was tossed near them and a new Smash appeared, looking at the new Smash, Sento said, "I'll draw the Smash's attention. You go!" He ran out and Ginny watched, worried for Sento, however, Sawa took her hand and ran to the boat to get away from the fighting. However, the boat owner said that he couldn't let them on cause it would cause trouble for the passengers. Ginny gasped, "No, so we're stuck." "Let them board." A woman called out, walking up. "I'll take responsibility."

As it turned out, it was the woman who Sento saved earlier, but Ginny kept looking back, worried for him. She sat with Ryuga and he asked, "Did he know I was going to do this?" "Sento-kun?" Sawa asked, "No way!" Ryuga repeated what Sento said and spoke, "I thought I saved Nabeshima's family, he'd testify and prove my innocence. That's why I wanted to save them. But... he's different. Even saving those two, all he did was smile." Ginny nodded with Sawa, smiling.

But she sighed, "Maybe I should have stayed." Sawa and Ryuga looked at her and she looked down, Sawa patted her shoulder and sat with her, trying to comfort her.

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Well, not much to say expect I really liked the fan art when this episode came and honestly, I would have to say HawkGatling is my favorite Best Match of Build. I'll let you know my other favorites later on.

Next chapter, the identity of the Smash is revealed, Ginny, Sawa, and Ryuga make it to Seito, Sento is poisoned, a new masked enemy appears, and Ginny and Sento consider their feelings. This has been WhiteRose-Aki, see you in the next chapter. If you enjoyed this chapter, please R&R.


	4. Evidence Becomes Zero

Welcome to the next chapter. A lot happened during the writing the chapter, including me helping with a Halloween event at my local church, but it's done. Along with volunteering and doing bowling, I'm trying to keep this on top. Now on the reviews:

GaoGod - While I thank you for reading and reviewing, may I ask something: Where are you seeing romance? Seriously, where are you seeing it or getting the idea of it? If you read all the current chapters so far, which I hope you have, I have put nothing of romance in the story. Ginny and Sento are close friends, almost like family members. I could have done this with Ginny doing Wizard's world but I didn't, this was requested by MaryamSahizaba who wanted to see Ginny in Build's world and I started to write to let them see the young Weasley in their favorite Rider. I won't deny there will be romance, but it will actually happen near the end of the story, the confirmation will be during the reveal of the real bad guy and the actual thing will be like the night before the final battle. And these 'delusional stories' of mine, as you call them, are pretty much me seeing if I can get a HP character to help KR characters, having them react in the situation and have a adventure outside of Hogwarts. While your review was hurtful, I don't see what you were getting at.

merendinoemiliano - Thanks for the review. I'll try to switch things up soon.

Disclaimer is that I own none of this. Kamen Rider Build is property of Shotaro Ishionomori and Toei TV, Harry Potter is owned by J. K. Rowling, the only thing I own is love of the two, the idea, and anything I might do in the story.

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Chapter 4 - Evidance Becomes Zero

Waking up from his recurring nightmare of being experimented on and seeing the mysterious Night Rouge along with a strange looking panel, Sento sat up gasping after feeling Soichi pulling his face and he shouted, "Ow!" Sento looked around and gasped for air, seeing he was back in the basement, laying on his bed. Last he remembered, he was poisoned after seeing that Nabeshima was the Smash and Ginny went with Ryuga and Sawa to Seito to find Nabeshima's family.

"Alright, you're revived!" Soichi said, smiling and looking relived. "You're okay now." "What are you doing?" Sento asked, looking confused. Soichi sat on the bed as he began to explain, "I found you unconscious at the warehouse, so I brought you back here. You were poisoned. You're lucky I found you in time." "It was a cobra..." Sento said, looking down. Soichi asked, "Cobra?" "I didn't see his face." Sento said, "But there was a cobra symbol on his chest. He looked vaguely similar to Rouge."

At that moment, his phone rang and breathed to hear Ginny on the other end, "Gin-chan? Have you and Banjo arrived in Seito?" "Yes." Ginny said, standing with Ryuga who was marking on a map their route. "We just arrived. The woman who Build saved earlier found out where Nabeshima's family and arranged for a car to take us there." "It's been pretty busy here too." Sento said, not showing he was relived that they made it safely. "That Smash was Nabeshima. But he got taken." "Are you sure?" Ginny asked.

"Nabeshima telling Banjo where his family is..." Sento said, sounding concerned, "might be a trap to lure Banjo there. Be careful." "Alright. Same with you." Ginny said. Then she ended the call, both her and Sento looked at their phones, and sighed, wishing that they could have said more but chose against it. Ryuga looked at her and Ginny composed herself, looking at him. "Nabeshima telling where his family is, Sento believes it might be a trap. We should be careful."

Ryuga looked at her and kept quiet, nodding. The two entered and kept quiet, having Sawa drive to the apartment building where Nabeshima's family was. Sawa smiled and said, "Man, that woman's a lifesaver! She even lent us Seito money!" "So which apartment is Nabeshima's family?" Ginny asked, looking at her. Finishing his sandwich, Ryuga said, "By finding Nabeshima's family." He stepped out but was grabbed by Sawa. "Wait!" She said. Ginny looked at him and asked, "Have you forgotten you're considered a criminal?"

"Not to mention, there's survillance cameras everywhere." Sawa said, pointing out at the cameras over the place. Now grumpy, Ryuga asked, "Then what should we do?" While thinking, the trio looked as a trunk pulled up and a passenger quickly run somewhere. Ginny noted the smile that appeared on Sawa and Ryuga, not sure what to think and nervously watched as their plan came to fruition, dressing up as deilvery people. Luckily, they were able to sneak past the person at the door and made it to the elevator.

Ginny breathed as Sawa smiled and said, "First obstacle cleared!" 'However, things might get harder from here.' Ginny thought, not showing her worry. So they headed to the apartment where Nabeshima was, and Ryuga rang the doorbell. As soon as the door slowly opened, Ryuga grabbed it and held it open, asking, "Are you Nabeshima's family?" Ginny facepalmed and thought, 'Idiot...' Now scared, the woman tried to close the door and Sawa stopped her, "Wait. You're making such a scary face!" "We're sorry for scaring you." Ginny said, looking at her and removing her hat. "But is your husband Nabeshima-san?" The woman looked at her and nodded, "Yes..."

"Okay, well, he's kinda in a bind at the moment." Ginny said. "But he asked us to protect you and your child." Sawa nodded and made Ryuga salute. So she let them into the apartment, Ginny sat on the floor, watching Nabeshima's young daughter try to do a cat's cradle on her fingers while Ryuga sat at the table. Sawa asked the woman, "Have you heard of a organization called Faust?" "He never told me anything about his work." She said. "He just suddenly told me we were going to Seito. Why did he leave us in such a dangerous place?"

Ginny and Ryuga looked at each other, the woman continued, "No matter what I asked, he just kept saying he was protecting our family..." "Hey, hey!" His daughter said, speaking up. Ginny and Ryuga looked at her, seeing her attempt of the strings on her fingers. "Pylon..." Ginny smiled, as the little girl said, "Tortoise... Eraser." She pulled her hands apart, trying to change it, "Helicopter! I'm amazing, right?!"

Ginny was surprised to see what looked like a smile on Ryuga's face, he said, "I've never done it before, so I don't know." 'I never imagined he had a nicer side to him.' Ginny thought, smiling. So she tried to explain the details of the string figure in her fingers. Sawa whispered to the woman, "Your husband might be putting himself in danger to protect his family. Let's hurry and go to him." His young daughter lit up at the idea to see her father again and Ryuga asked, "Do you love your papa that much?" Ginny looked at him, curious. The girl smiled, "Yup. I super love him! When I show him my cat's cradle, he'll say 'Haru-chan, you're amazing' and praise me lots and lots!"

'Dad...' Ginny thought, thinking of her own father. So Ryuga hid them in the box and tried to sneak quietly, but suddenly robots from Faust appeared, attacking him. Sawa burst in, driving the van with Ginny holding on for dear life, Sawa said, "Get in!" So once they got in the van, she drove off. "I made it in time somehow." Sawa said, "We should be able to see the boat..." But suddenly one of the robots jumped on the van, scaring everyone. Sawa said, "What's going on?!"

Seeing a sudden timer appeared, Ryuga asked, "Is that timer...? A bomb?!" "We need to get out of the car." Ginny said, panicking. Ryuga poked his head out and shouted to the people at the boat to start it and Sawa said, "We're jumping!" "Sawa, are you insane?!" Ginny asked, her question was ignored as everyone in the car jumped out and the car drove off the edge, they all managed to land on the boat while the car went into the water as it exploded, Sawa shouted, "We're saved!" "I am never riding in a car with you again, Sawa." Ginny said, catching her breath.

They rode the boat back to Touto, and as soon as it docked, Ginny and Ryuga ran to find Sento. Going to a children's park, they found him in combat with the Smash he fought before, though it was larger then he was. Ginny gasped as he was about to be hit, but Ryuga grabbed the Drill Crusher and shook the Dragon Fullbottle, tossing the weapon in the Smash's side. "Sento!" Ginny shouted, having him look at them, sounding shocked.

"Banjo! Gin-chan!" He said, starting to stand up. Ryuga shouted, "Now! Go!" "Perform the finisher on the Smash!" Ginny shouted. Sento nodded, "Okay!" Changing his form, Sento changed into HawkGatling, in order to protect itself, the Smash summoned square pillars from the ground, so Sento prepared the finisher move. Once it was fully charged, he fired the Hawk Gatlinger to perform the finisher move. "Alright!" Ryuga smiled.

Ginny kept quiet as Sento landed and the Smash fell to the ground. Sento changed back to his civilian form and grabbed the Drill Crusher. "I can't believe you managed to toss this." He said, Ginny looked at Ryuga and said, "That was quite the arm on you." "My pecs are the real deal!" Ryuga said, smiling at them. Ginny sighed, "Alright, big guys, shrink the ego." "It was thanks to the Dragon Bottle." Sento said, surprising both of them. He held out one of the bottles and captured the essence of the Smash, revealing it was Nabeshima.

Gasping, Ginny covered her mouth as Sento said, "Nabeshima..." The trio took him back to the cafe, Ginny kept quiet, sitting on her bed while Sento, Misora, and Ryuga were quiet as well and sat in the room, the four of them waiting for Nabeshima to wake up. When he did, Ryuga asked, "You're finally awake?" "You okay?" Ginny asked, looking at him. Ryuga grabbed his shirt and asked, "You remember my face, don't you?" "Who are you?" He asked, removing his hand. Ryuga said, "If that was a joke, it wasn't funny. I'm Ryuga Banjo." "I don't think it was a joke." Ginny said, standing up.

"I don't know you." Nabeshima said, backing away. "Who am I?" Ginny held her arm as Ryuga angrily kicked the bed post, he shouted at Nabeshima, grabbing his shirt. "Stop screwing with me!" He shouted. "If you can't testify to prove my innocence, who will?!" Getting annoyed with his anger issues about his innocence, Ginny shouted, "Ryuga, stop!" Sento touched her shoulder and walked up calmly, then Sawa and Nabeshima's family came up. "What's the matter?" Sawa asked.

Gasping for air, Ryuga stepped and Ginny didn't look as Haru ran to her father but he pulled her away. Sento said, "He seems to have lost his memory." While his wife ran to him and Haru tried to show her cat's cradle, Ginny sat on her bed and looked down, trying not to imagine what would happen if she lost her memory or even she became a Smash.

But she looked up when Ryuga said, "Look at it. She praticed hard so she could show it to you. She loves you... She wants your praise... My problem isn't important." He tried hard not to cry, saying, "But at least remember her... Remember your family!" Ginny was surprised to see this side of Ryuga and held herself, thinking of her family and how they might be doing. Ryuga got on his knee and said, "Please... Remember them." The room was quiet, but Sento grabbed something at his desk and said, "Haruka-chan."

He showed her a light bulb and box and explained, "Your papa had his happy memories of you taken. Like this." He took out a battery and turned off the bulk, and said, "So... You and your mama need to make some new memories with him. If you do..." He made a battery which turned the bulb on again, "I'm sure they'll return." 'I wasn't expecting any of this...' Ginny thought, smiling. 'Neither from Sento or Ryuga...' "Okay!" Haru said, smiling. "Then I'll teach you cat's cradle, papa!"

"I'll take care of them and bring them somewhere safe." Sawa said, walking up to the reunited family. Ginny said, "Thanks, Sawa." Before Nabeshima left, he went to the wall and saw the panel. He said, "Those bottles... I saw them at their place too." 'He's seen the FullBottles?' Ginny said, standing up. Ryuga asked, "Wait, isn't Misora the only one who can create these bottles? Then why does Faust have them?" "Misora?" Ginny asked, looking at her. So after Nabeshima left, Sento took a hammer and hit the wall, smashing it.

Ginny, Ryuga, and Misora kept quiet, watching him. Soichi came in and tried to stop him after it was pointed out to him by Misora, but by then, the damage was done and Sento pulled out the panel, looking at Soichi. "A panel from Pandora's Box." Sento said, when asked what was it. Ginny covered her mouth. Sento asked Soichi, "Why do you have this? Answer me!" There was a moment of quiet before Sento asked, "Are you a member of Faust?"

Soichi kept quiet and looked at him.

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Then a couple of episodes later, Soichi completely changes sides, which is one of the many twists of the story. So, yeah. But the actual episode was nice too, can't say what I think of this episode. But I liked that Sento and Ryuga tried to cheer up Haru, it was so sweet.

Next chapter, Soichi reveals his connection to Faust, Ginny thinks of leaving the cafe, a new Rider appears and captures someone, someone who knows Sento's past appears. This has been WhiteRose-Aki, see you all in the next chapter. If you enjoyed the chapter, please R&R.


	5. Dangerous Identity

Hi, everyone! Welcome to chapter 5 of Build x HP, it took a while cause I took Christmas and New Years off, and wanted to update the story before the long-awaited release of Kingdom Hearts 3 which will cause me to disappear for a month... again. Sorry. But I will try to get more chapters out and show how Ginny can help in the world of Build and learn about the wonders of muggle technology. Thanks for all the favorites and followers.

merendinoemiliano - Yeah, true. And I would like to note that in the first chapter, I clearly stated that Sento had seen Ginny use magic to transfigure herself a wardrobe to wear, and he didn't mind it.

MaryamShibazada - Thank you for the wonderful review.

Disclaimer is that I own nothing of this, just the idea and the crossover. Harry Potter belongs to J. K. Rowling and Bloomsbury Publishing, Kamen Rider Build belongs to Shotaro Ishinomori and Toei TV.

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Chapter 5 - Dangerous Identity

Ginny kept quiet, her hand over her mouth as she tried to process what Sento was asking. Was it possible that Soichi, the man who was kind enough to take her and Sento in when they had no other place to go, was a member of the group who did experiments on Sento, Ryuga, and Nabeshima and made Sento lose all his memories of his life

She continued to keep quiet as they headed into the cafe and Soichi began to brew his coffee, he explained, "This is my original blend to compete with the cafe I work at part-time. I call it 'Nascita de nani shita?'"

"So, what's going on?" He said, looking at them. Ginny looked at him and said, "Soichi-san, please. Don't act naive. The panel Sento found was stolen from the Institute by Faust." Sento showed the panel that they had found in the wall, Ginny asked, "Why do you have it?"

"You're a member of Faust, aren't you?" Sento said, looking at him. Soichi looked serious for a moment, "I'm... Faust... he says." But he suddenly laughed with Misora, Ryuga shouted, "What's so funny?"

"Have you ever seen such a stylish bad guy before?" Soichi asked, trying to look cool with his hat tilted. Ginny thought to herself, sweatdropping on whether to answer or not, 'Debating to myself if I should say yes cause while he was a major pain in the butt, Draco Malfoy was pretty stylish and he was a bad guy for a while, nearly my school life at Hogwarts.'

"Then what about the panel?" Sento asked, holding the panel in his hand. Misora spoke, "That's from when I was captured by Faust." "You were captured?" Ginny said. Misora nodded, "Yes. I've got the power to purify Smash elements, right? So Faust was after me. But Dad saved me." "When I rescued Misora from their hideout, I took the panel and bottles." Soichi said, stepping out from behind the counter.

"So the reason you never go outdoors.." Ryuga realized, looking at Misora. Misora finished his sentence, "... is because Faust is still after me! And Dad had a different job too." "This." Sento showed Ryuga a picture of Soichi when he was a astronaut. Ryuga was shocked and asked, "You were an astronaut, Master?!"

"You knew?" Soichi asked, smiling. Ginny said, "Sento told me how you were the one who found Pandora's Box on Mars, right?" "The one who released the light from Pandora's Box and caused the Skywall tragedy was also you." Sento said, pointing at him.

"I went a little crazy due to Mars' influence." Soichi said, rubbing his neck. "I still don't know why I did that." He and Sento began to play foosball and Sento said, "I heard you were also the one who helped Faust the panels."

Soichi smiled, "I did that to save Misora. In order to infiltrate their hideout, I had to get Faust to trust me as a ally." "So why didin't you return the panel to the government?" Sento asked, Ginny was amazed that they could talk and focus on the game they were playing. Soichi said, "Return? Faust could force their way into the Institute if they really wanted." "Then why didn't you tell me?" Sento asked.

"Because I wanted you to become Build." Soichi said, surprising Sento. Ginny looked at Soichi as he explained, "I can't forgive Faust. They kill people like they're mere bugs. But Misora and I couldn't do a thing. Then when I met you and Ginny-chan. I thought you could use the bottles' power for good and defeat Faust. But if I told you everything, I wasn't sure if you would help me. So I decided I wouldn't tell you about the panel until you discovered it yourself."

"So that's why you made me work at the Institute?" Sento said, sighing. Ginny smiled, breathing in relief. Sento thought and said, "If I researched Pandora's Box, I'd evenutally find out about this... So it was all as you planned." He took a cup of the coffee, sipping the cup. Sento sighed, "Can't be helped then. In light of your courage to try and sell such terrible coffee, I'll forgive you."

Ginny laughed, smiling. Ryuga groaned and shouted, "Seriously?! You're too soft-hearted!" "If people weren't soft-hearted, they'd never try this obviously horrible coffee once they heard the terribly puny name." Sento said, looking at him. Soichi retorted, "It's not that bad." Ginny, Misora, Soichi, and Ryuga took a cup and took a sip of coffee, before spitting it out. Ginny said, "Sorry, Soichi-san, but that's not coffee."

While the rest of the group tried to get the awful taste out of their mouth, Sawa came in and smiled, "I have a scoop! I found someone who knows Sento-kun's past!"

So Ginny went with Sawa and Sento to meet the person who knew Sento's past, however, Sento wasn't sure about the meeting and asked Sawa, "How do you know this person knows my past?" "I asked around with your photo and a music club owner led me to a member of your band." Sawa said, showing his photo on her phone.

Ginny looked at him and asked, "You had a band, Sento?" "I was in a band?!" Sento said, surprised. Sawa nodded and said, "Apparently you lived with a younger classmate called Kishida Tatsuya-kun."

"Aniki!" Somone shouted, they looked and saw a slightly chubby young man wearing a afro, a tank top, glasses, sweat pants and shoes. He excitedly ran to Sento to hug but as if on instinct, Sento tossed him to the ground, Ginny and Sawa just looked at him with surprise and quiet shock, as did the passersby in the area. Realizing what he did, Sento led everyone to a area that wasn't as crowded. Once there, Tatsuya gave Sento's real name

"Satou Tarou?!" Sawa asked, Ginny put her finger to her chin, thinking to herself, 'I personally prefer Sento.'

"Yeah, that's your name, Aniki!" Tatsuya said, getting disturbingly close to Sento. Sento almost fell back in shock, as they followed Tatsuya, Sawa asked, "Sento Kiryu isn't your real name?" "Master gave me that name." Sento said. "I had no identification with me when he found me. Gin-chan was the same, but she remembered her name, just not how she ended up where Master found her."

"But Satou Tarou..." Sawa said, laughing. Sento said, "I just can't get it through my head." "You really can't remember anything?" Tatsuya said, looking at him. So he showed them a regular-looking apartment, "This is it, Aniki! This is the apartment where I lived with you!"

"No way..." Sento said in disbelief. Tatsuya led them into the apartment, and the three of them were hit with a awful mess as the entire apartment was a mess. Sawa shouted, "What a mess!" "It completely smells in here!" Ginny said, covering her nose. Tatsuya asked, "Do you remember anything now, Aniki?"

"Not a thing..." Sento said, looking around. "And I definitely couldn't have lived here!" Sawa quickly went to open the window, Sento told him, "I'm a neat freak! You must've been mistaken." "Uh, Sento..." Ginny said, looking at the photos on the wall. Sento kept quiet as he saw them and they all had a familiar looking young man in a red jumpsuit with his hair in a weird spiky style. Sawa gasped, "You really were in a band!"

Sento went to sit by the window to let it sink in, and Ginny looked at him, wondering what was going on in his head at this revelation. Tatsuya said, "Aniki, you always used to say if you were famous, you'd marry a TV announcer, eat a hundred bowls of egg eyudon, and a buy a thousand buildings!"

Ginny cleared her throat, "Um, Tatsuya-san, we were curious." "When did Satou Tarou disappear?" Sawa asked, Tatsuya thought and said, "I'm sure it was September 5th... yeah." "Sento..." Ginny said, looking at him. Sento looked at her, shocked, "That's the day Master found me and you."

He led them to the alleyway where he was found, Sawa asked, "How did you collaspe?" "Just normally..." Sento said, pointing to the spot. Ginny thought about this, they were found on the same day but Soichi found him awake while she was unconscious when she was found. Sawa put him in the spot and said, "Do it!" Ginny looked at her, confused.

She watched as she tried to get Tatsuya to see if he recongized the area and Ginny looked around, trying to find where she was found. Ginny turned to look at Tatsuya who explained that Satou went somewhere for a part-time job to test some kind medicine for something. Suddenly Sento went to him and asked, "Can you give me more details?"

Before he could, there was a shout and they ran to see Faust mechas scaring construction workers, Ginny watched as Tatsuya bumped into Sento before he could transform into Build. Then government guardians appeared and the group hid to see the Guardians finish the Faust mechas but suddenly they turned on the workers, attacking them.

"Why did the Guardian turn into Faust mechas?" Sawa asked, worried. Sento transformed into Build, using the Taka and Gatling bottles before running into the fight. Even though he saved the workers, they ran away because Build was a wanted criminal. Ginny walked up beside him and took his hand to help comfort him. But they suddenly heard a voice.

"So the hero of justice appears?" The voice asked, Sento turned to see the red armored being, asking, "Cobra?" "Wrong~! The correct answer is Blood Stark!" It said, Ginny thought, 'Blood Stark?'

"You're the one who turned Nabeshima into a Smash!" Sento shouted. Blood Stark said, "You got it right this time! As your reward, I'll play with you!" He pulled out a weapon and fired at everyone, Ginny felt Sawa cover her as they and Tatsuya fell to avoid the bullets while Sento used the wings to fly around and fight Blood Stark, getting him to fall on the ground.

Once he was on the ground, Sento changed to RabbitTank, running to fight. Ginny looked at him, worried since Blood Stark could be stronger than him like Night Rouge. Sawa was just busy taking photos for the fight while Ginny and Tatsuya were worried about Sento. Sento attempted to do his finishing kick on Blood Stark, but Blood Stark grabbed his foot. Ginny and Sawa gasped at what they saw.

"Nick kick!" Blood Stark said, before tossing Sento to the side. "Hazard Level 3.2. You've got room to improve. See you!" 'Hazard level?' Ginny pondered before running to Sento, she knelt down to him and asked, "Sento, are you okay?" "Yeah." Sento said, nodding. "What's with that guy?"

They all headed to the cafe, Ryuga saw them and said, "Finally! That took forever!" Ginny rolled her eyes at he contiued while Tetsuya tried to talk about the cafe, "Do you know how long I've been waiting?! SHUT UP!" Tetsuya shook scared at Ryuga's aggressive attitude, looking at Tatsuya in his attire, Ryuga asked, "Who's this weirdo?" "Apparently, he's Sento's old classmate and friend." Ginny said, looking at him.

She was wide-eyed to see Ryuga headbutt him and knock him out, she thought, 'He's more hard headed than I thought.' She groaned after that when he whispered to Sento, "Can you think of a way to prove my innocence?" 'I take that back...' She thought, sweatdropping and shaking her head in her hand in her face.

"Shut up." Sento said, looking annoyed. "I've got my hands full with this Satou Tarou thing." "Who's Satou Tarou?" Ryuga asked, Ginny told him, "It seems that's who Sento used to be before he lost his memory."

After Misora cheered at completing her puzzle, she said, "I made a bottle too." Sento's tuft of hair went up and he looked excited, "You're kidding! How exciting!" He went down to the lab and Ginny sighed, not seeing Ryuga headbutt Tatsuya again after he thought he was the escaped murderer that the news called him. "I didn't kill anyone." Ryuga said, grumbling.

"Didn't you kill Katsuragi?" Tatsuya asked. Ryuga said, "I just saw his body." "Apparently he's innocent." Sawa explained.

Still unconvinced, Tetsuya left the cafe, Ginny shook her head. "Way to go, Ryuga-kun." She said, grabbing him from stepping outside. So they went down to the lab where Sento, acting like a child, tried to figure out what organic bottle worked with the new Comic Bottle. Ginny laughed, while Ryuga still wanted his innocence proved, Sento said, "This is for your sake too."

"What do you mean?" Ginny asked. Sento said, "It was Faust that used Nabeshima to set him up, right? So if we discover their hideout and the full story, we can prove your innocence too. For that..." While he was talking, they found that Ryuga picked and discovered the Ninjya bottle was the Best Match for the Comic Bottle.

Seeing that, Sento's tuft disappeared and wept, "No way..." "Satifised?" Ryuga said. "Now about my problem..." Then Sento screamed, making Ginny and Ryuga jumped as he shouted, "In that case, I need a weapon!" He began to write on the clear board about the kind of weapon the new Best Match, so since he was so absorbed in making the details of the weapon, Ginny and Ryuga went to lay on the bed, Ginny fell asleep while he was working on the blueprint.

"Done!" Sento shouted, making Ginny wake up and yawn. "I call it... Four-Panel Ninpou Sword!" He revealed his new weapon, which was a sword with four comic panels on the blade. Ginny rubbed her eyes and gathered some clothes to get changed into a fresh set of clothes. She went to the changing room and began to change her clothes. While she was changing, Misora checked her idol site and said, "I got a Smash report. Apparently, it's heading to your Institute, Sento."

"Why is it going to the Institute?" Ginny asked, tying her hair into a ponytail and styling it into a bun. Misora said, "Maybe it's after Pandora's Box?" "Then Master was right." Ryuga said, sitting on the bed. "It's a good idea to keep the panel here after all." "By the way, where is Soichi-san?" Ginny asked, checking herself over. "He's been gone for a long time."

Misora and Sento had no answer so Sento grabbed his coat and Driver as Ryuga said, "Just let the government special forces deal with it. You can't expect to transform and fight there anyway!" "Just gonna take a look." Sento said, Ginny thought and said, "I'm coming with you!" They went upstairs and rode out to the Institute, watching the new Smash fight the guards.

"So the fugitive can't do anything but watch?" Blood Stark asked, appearing behind them. Ginny stayed close to Sento as he said, "Do you know who that Smash is? Here's a hint. Aniki~!" "No..." Ginny gasped as Sento looked shocked. "Tatsuya!"

"Correct!" Blood Stark said. "But don't get the wrong idea. He volunteered for the experiment. What a brave man. Still, he's just a hopeless fool." "Stop screwing with me..." Sento said, getting his Driver out. Ginny gasped, "Don't, Sento! As Build, you're a wanted criminal!" He transformed into Build and went to attack Blood Stark.

Ginny looked worried as Sento tried to fight Blood Stark, swinging his weapon but Blood Stark managed to block til Sento was about to push him back and tried to perform his kicking kick. While he was able to damage his arm, Sento was still sent flying as Ginny covered herself from the blast. Blood Stark noted, "Hazard Level 3.7? So anger increases the level..." " 'That again.' Ginny thought. 'What is a Hazard Level?'

"Just as I hoped." Blood Stark said, looking thoughtful at Ginny and she gasped. "Hurry up and save your Smash." He walked away and Sento groaned, running to help his friend in trouble. Ginny didn't watch the fight as she looked pale at the thought if her brother or friends coming and getting changed into Smashes that Sento would have to fight.

"Ginny!" Ryuga shouted, she turned to see him. "Go with Sento. I'll handle the government guys here!" "Okay." Ginny nodded, running to her quad bike and putting her helmet on, riding after Sento who rode to a empty location, tossing his friend on the ground. She watched him use his new bottles, changing into a yellow and purple colored Build.

'So that's the new Best Match?' She thought, looking at the new form and watching him use the special ability which allowed him to make copies of himself to rapidly slash at the Smash then performed a slash at him before the Smash fell to the ground and Sento extracted the Smash element from his friend.

Walking to him, Ginny watched as he went to Tatsuya's side and he revealed the reason Satoru went for the part-time job was cause he thought they were pressed for money, and that he just wanted to help him, but he couldn't, calling himself useless. Ginny kept quiet as Ryuga came up, but gasped as Ryuga punched him in the stomach and took the bottle, giving him the element back.

"Ryuga, you coward!" Ginny shouted, crying as he hid behind his bike and the Smash walked off.

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And for that, I really began to dislike Ryuga. I mean, he was okay, but in these early episode, he was the spitting image of being a hard headed idiot since all he cared about proving his innocence. And this kinda ruined his character for me.

Next chapter, the group finds Faust's base, Ginny gives Ryuga his just due to his actions, Sento truly saves Tatsuya, Sento and Ryuga began to fight each other, Ginny gets captured by Blood Stark. This has been WhiteRose-Aki, see you all in the next chapter. Please R&R if you enjoyed the chapter.


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